A SpaceX Falcon 9 rocket launched from Cape Canaveral Thursday, carrying a payload of three very different spacecraft: an Indonesian telecommunications satellite, an experimental spacecraft for the US military and the first commercial mission to attempt a landing on the Moon. Falcon lifted off from Space Launch Complex 40 (SLC-40) at the opening of a 32-minute window at 20:45 Eastern Time (01:45 UTC on Friday).
The primary payload for Thursday’s launch was Nusantara Satu, a high-throughput communications satellite that will be operated by Indonesia’s PT Pasifik Satelit Nusantara (PSN). However, much attention in the build up to launch has been paid to the Israeli Beresheet spacecraft that is piggy-backing on the Falcon 9 launch.
Beresheet will attempt to become the first Israeli spacecraft, and the first privately-operated mission, to land on the Moon. The third satellite aboard Thursday’s launch is S5, a space situational awareness demonstrator for the US Air Force Research Laboratory which will be deployed by Nusantara Satu at a later date.
Previously known as PSN VI or PSN-6, the Nusantara Satu satellite was built by Space Systems Loral around the SSL-1300 platform. Bound for a slot in geostationary orbit above the Earth’s equator at 148 degrees East, Nusantara Satu carries 26 C-band and 12 extended C-band transponders and eight Ku-band transponders which will produce spot beams. The satellite offers a total bandwidth of 15 gigabits per second.
The 4,100 kilogram (9,040 lb) Nusantara Satu spacecraft is expected to operate for at least fifteen years. It will provide communications links to rural parts of Indonesia, allowing PSN to expand broadband internet services into these regions. Nusantara Satu is equipped with electric propulsion which will be used for orbit-raising maneuvers: Falcon 9 will drop the satellite off in an elliptical transfer orbit, with Nusantara Satu using its own engines to reach its final geostationary slot.
Once it has arrived in geostationary orbit, Nusantara Satu will deploy its subsatellite, S5. This is the US Air Force Research Laboratory’s space situational awareness experiment – a 60 kilogram (130 lb) spacecraft that will detect and track objects in orbits close to the geostationary belt.
S5 was constructed by Blue Canyon Technologies, with its instruments provided by Applied Defense Systems. The data it collects will help the Air Force to update its satellite catalog with accurate orbital parameters for these spacecraft and debris objects. S5 is intended as a proof-of-concept to demonstrate that low-cost miniature satellites can be used for accurate tracking of geostationary satellites. It is expected to operate for one year.
The other payload aboard the Falcon 9 was Beresheet, a Lunar lander developed by Israel’s SpaceIL. Taking its name from the first words of the Book of Genesis – in the beginning – in Hebrew, Beresheet will attempt a soft landing in the Moon’s Mare Serenitatis region. If successful it will be not only Israel’s first mission to the moon, but the first spacecraft to land on the Lunar surface that was not funded or operated by a government space agency.
The Soviet Luna 9 spacecraft was the first to make a soft landing on the moon – touching down on 3 February 1966. It was followed by further unmanned missions in the Soviet Luna and American Surveyor programs, and the manned landings of the US Apollo program from 1969 to 1972. To date, only the Soviet Union, the United States and the People’s Republic of China have landed spacecraft on the moon. China’s Chang’e-3 and Chang’e-4 missions, which arrived in December 2013 and January 2019 respectively, are the only spacecraft to have landed on the Lunar surface since the mid-1970s.
SpaceIL is a non-profit organization that was formed to compete for the Google Lunar X-Prize, a competition organized by the X Prize Foundation and financed by Google which would have awarded twenty million US dollars for the first privately-funded spacecraft to land on the Moon, with a further ten million dollars for other achievements. The rules initially stipulated that the prize would have to be claimed by the end of 2014, and while this was extended several times no competitor was able to launch their mission before the reward finally expired last March.
Despite no longer qualifying for the reward, SpaceIL and several of their competitors have pressed ahead with their landers, with Beresheet the first of these to make it to the launch pad.
Although it will attempt to become the first privately-operated spacecraft to land on the Moon, Beresheet will not be the first commercial spacecraft to visit Earth’s natural satellite. In late 1997 the Blok-DM3 upper stage of a Russian Proton-K rocket malfunctioned, leaving the AsiaSat-3 communications satellite stranded in an unusable orbit. Renamed HGS-1 and under the ownership of Hughes Space and Communications, the satellite flew past the Moon in May 1998 to gain a gravity assist as part of a complex series of maneuvers that eventually saw it reach geosynchronous orbit.
After Falcon 9 deployed it into a supersynchronous elliptical transfer orbit, Beresheet will make a series of orbit-raising maneuvers over the course of several weeks in order to reach the Moon. With an on-time liftoff, Beresheet will be expected to arrive in Lunar orbit on 4 April, with its landing a week later.
Beresheet was constructed by Israel Aircraft Industries, the country’s largest aerospace manufacturer, and incorporates guidance and control, communications, power-generation, propulsion and landing systems as well as cameras and scientific instruments. The lander has four legs that will support it and provide a stable footing on the surface – these include aluminum honeycomb shock absorbers that will be crushed on touchdown, absorbing energy to protect the rest of the spacecraft. Solar panels provide power.
At launch, Beresheet has a mass if 600 kilograms (1,320 lb), including the propellant that it will expend getting to the Moon and making its landing on the surface. By the time it has landed on the Lunar surface, this mass will have fallen to around 160 kilograms (350 lb). Beresheet stands two meters (5.5 feet) tall, with a diameter of 1.5 meters (4.9 feet). In addition to scientific instruments, a digital time capsule and Israeli flag are also aboard the lander.
Once on the surface, Beresheet will use a magnetometer to study magnetic fields at its landing site. Mare Serenitatis was chosen because of known magnetic anomalies that the spacecraft will be able to study.
Beresheet also carries cameras and a retroreflector provided by NASA that can be used for laser ranging experiments – where laser pulses are fired at the spacecraft and reflected back, allowing the distance between the observer and spacecraft to be measured. NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft will use its suite of instruments to search for signs of the elements hydrogen and mercury in dust stirred up by Beresheet as it lands.
Nusantara Satu, S5 and Beresheet shared the first leg of their journey to orbit aboard SpaceX’s Falcon 9 rocket. Thursday’s launch marked the sixty-eighth flight of Falcon 9, which was introduced in 2010. Falcon 9 is a two-stage rocket incorporating a reusable first stage which can fly back to Earth after completing its role in its mission. The first stage used for Thursday’s mission was Core 1048, which already has two previous launches under its belt.
Core 1048 first flew last July as part of a Falcon 9 which deployed ten Iridium-NEXT communications satellites, and made its second flight in October with Argentina’s radar imaging satellite, SAOCOM-1A. Thursday’s launch saw it become the second core to make three trips into space, after Core 1046 which made its third flight in December. The ability for Falcon 9’s boosters to make three or more flights stems from the Block 5 upgrade that was introduced last year – earlier versions of the stage were limited to two launches each.
Recovery of Falcon 9’s first stage involves a series of engine burns culminating in a powered landing either back at the launch site or aboard an Autonomous Spaceport Drone Ship (ASDS) downrange of the launch site.
The entire East Coast SpaceX Fleet is docked together. We are waiting to see the net go up as the arms are already in place. What a beautiful afternoon in @PortCanaveral. #SpaceXFleet @SpaceX pic.twitter.com/0Ar84ySxiS
— Julia (@julia_bergeron) February 14, 2019
Return-to-launch-site (RTLS) landings are typically used on launches to low Earth orbit where performance is at less of a premium, while the ASDS is used on higher-energy missions where more performance is needed towards the primary mission and it is not practical for the booster to alter its course back towards the launch site – instead the ASDS can be positioned along its expected course. Thursday’s launch saw Core 1048 land aboard the ASDS, Of Course I Still Love You, in the Atlantic Ocean.
As well as the first stage, SpaceX has been making strides towards a reusable payload fairing for Falcon 9. The payload fairing, which encloses the satellites during the early stages of flight to protect them from the atmosphere and preserve the rocket’s aerodynamic profile, splits into two halves and is discarded to save weight once the rocket reaches space. SpaceX has outfitted the two halves of the fairing with maneuvering thrusters and parafoils to enable a controlled reentry and descent. A specially modified ship will then catch the fairing using a giant net, and return it to land.
All of SpaceX’s attempts to catch Falcon’s payload fairing to date have come on West Coast launches, using the ship Mr Steven based out of the Port of Los Angeles. In early February Mr Steven passed through the Panama Canal and arrived in Port Canaveral to support Thursday’s launch, which was to mark the first fairing recovery attempt on an East Coast launch. However, poor sea states saw the attempt cancelled in advance.
At this stage SpaceX’s recovery of the fairing is experimental, and while they have been able to pick several fairing halves out of the water, Mr Steven has not yet proven her ability to catch one as it descends. Intercepting the fairing before it hits the water is important, as this reduces contamination that would be caused by the salt water.
Falcon lifted off from Space Launch Complex 40 (SLC-40) at the Cape Canaveral Air Force Station. SLC-40 is one of two operational Falcon 9 launch complexes on Florida’s Space Coast, along with Launch Complex 39A at the nearby Kennedy Space Center. SLC-40 was built for the Titan family of rockets, supporting Titan III and IV launches between 1965 and 2005. SpaceX has modified the complex since leasing it from the US Air Force in 2007, removing the fixed and mobile service towers and constructing a hangar to support horizontal integration of the Falcon 9.
Fuelling of the Falcon 9 for Thursday’s launch began with the flight director verifying that the rocket was in a good condition to begin loading, about 38 minutes before liftoff. Propellant began to flow into the rocket’s tanks about three minutes later, as will oxidizer into the first stage tank. Oxidizer loading onto the second stage began later, about sixteen minutes before liftoff. Both stages of the Falcon 9 burn RP-1 propellant – rocket grade kerosene – oxidized by subcooled liquid oxygen. This is liquid oxygen that has been cooled far below its condensation point, allowing it to be stored more densely in Falcon’s tanks.
The final minutes of the countdown saw the first stage engines chilled down to prepare for startup, while Falcon transfered to internal power and critical systems were brought online and into flight configuration. The Strongback transporter/erector opened its arms and retracted slightly away from the rocket, ready to retract the rest of the way when Falcon lifted off. The Strongback is a structure that is used to transport Falcon 9 to the launch pad, erect it to the vertical position and to provide connections for umbilicals that detach at liftoff.
One minute ahead of liftoff, Falcon’s onboard computers begin their final checks and the propellant tanks were pressurized for flight. With forty five seconds to go the Launch Director gave a final confirmation that the rocket was “go” for launch.
About three seconds before the countdown reached zero, Falcon’s computer commanded the nine Merlin-1D engines at the base of the first stage to ignite. The rocket was held down while the engines built up to full thrust, with liftoff taking place at the T-0 mark. Falcon climbed away from Cape Canaveral on an easterly trajectory, passing through maximum aerodynamic pressure, or Max-Q, about sixty-seven seconds into the flight. The rocket’s speed reached Mach 1, the speed of sound, at about the same time.
After a two-minute, thirty-seven second burn, Core 1048 shut down its engines – an event designated main engine cutoff (MECO). Falcon’s first and second stages separated three seconds after MECO, with the second stage beginning its first engine burn eight seconds later. Fifty-eight seconds into the burn Falcon’s payload fairing separated.
SpaceX recovered the first stage but not the payload fairing during Thursday’s launch. After separating, Core 1048 reoriented itself to reenter the atmosphere. As it passed back into the atmosphere the stage restarted a subset of its engines in a short entry burn, slowing its descent to reduce heating. This burn concluded a little under four minutes after separation after which the booster fell towards the Atlantic Ocean, where SpaceX’s Autonomous Spaceport Drone Ship, Of Course I Still Love You, was waiting. The stage restarted its engines again just before its landing – planned for eight minutes, 32 seconds mission elapsed time – slowing it to a gentle touchdown on the deck.
The fairing recovery attempt involves one or both halves of the payload fairing make a controlled reentry, using thrusters to orient themselves so that their outer shells offer protection from heating during reentry. As they descend, parafoils will be deployed to slow the fairing halves and allow their descent to be controlled. Mr Steven attempts to maneuver underneath each part of the fairing and catch it before it hits the ocean.
One of Mr. Steven’s final West Coast fairing recovery tests before shipping out for the East Coast. Wait for it… pic.twitter.com/A7q37Gpllu
— SpaceX (@SpaceX) January 30, 2019
While recovering assets are important for SpaceX’s goals to lower the cost of access to space, they were not crucial to the success of Thursday’s launch. Falcon’s primary mission was to deliver its three satellites, and while the first stage was returning to Earth, the second stage was continuing its journey to orbit. The second stage is powered by a Merlin Vacuum (MVac) engine, a version of the Merlin-1D that is optimized for the vacuum of space. Its first burn, which began after stage separation, lasted six minutes and 19 seconds and ended about 25 seconds before the first stage touched down aboard Of Course I Still Love You.
After the first burn is complete – an event designated second stage engine cutoff 1 (SECO-1) – the mission entered a coast phase. A second burn began eighteen minutes and 55 seconds later, lasting 65 seconds to inject Nusantara Satu, S5 and Beresheet into a supersynchronous transfer orbit with an apogee of about 60,000 kilometers (37,300 miles, 32,400 nautical miles). After the end of this burn, SECO-2, Falcon again briefly coasted as it oriented itself for spacecraft separation.
Beresheet separated first, five minutes and 31 seconds after SECO-2, with Nusantara Satu following ten minutes and 59 seconds later. S5, attached to Nusantara Satu, will separate once both spacecraft reach geostationary orbit.
Thursday’s launch was the second of the year for SpaceX, following on from the successful launch of ten Iridium-NEXT satellites last month – completing SpaceX’s deployment of Iridium’s entire second-generation constellation of satellites. Falcon 9’s next launch is currently slated to be the first test of the Dragon 2 spacecraft, designed to carry crew to the International Space Station under NASA’s Commercial Crew program. This test flight, which will not carry a crew, is slated for liftoff at the beginning of March.